1. Field of the Invention
The present invention relates to a battery module, a battery system, an electric vehicle, a mobile unit, an electric power storage device, a power supply device, and an electric device.
2. Description of the Related Art
Battery modules including a plurality of rechargeable battery cells are used for mobile units (e.g., electric cars) or power supply devices that store electric power. In order to detect charged conditions of the battery cells, it is necessary to detect terminal voltages of the battery cells in the battery modules.
For example, Japanese Patent Laid-Open Publication No. JP 2010-205,509 A discloses a battery system that includes a battery block constructed of a plurality of rectangular battery cells. An insulating plate is arranged on or above the battery block. Bus bars and lead wire lines are constructed integrally with the insulating plate. The plurality of battery cells are connected through the bus bars to each other. Terminal voltages of the battery cells are detected through the lead wire lines. The electrode terminals of the battery cell adjacent to each other are connected through the bus bars to each other. The lead wire lines are connected to the bus bars inside the insulating plate, and are drawn out from the insulating plate and connected to a voltage detection circuit.
Also, Japanese Patent Laid-Open Publication No. JP 2003-45,409 A discloses a power supply device that includes a battery assembly including a plurality of batteries, an insulating plate (referred to as measurement main unit), and a flat circuit unit. The flat circuit unit may include a control unit that adjusts voltages of the plurality of batteries to a common certain voltage. Terminals of the battery are arranged on the upper surface of the battery assembly. The insulating plate and the flat circuit are placed onto and cover the upper surface of the battery assembly. The terminals of the battery extend through terminal through holes in the insulating plate, and are connected to a conductive layer of the flat circuit unit.